Conventionally, nickel alloys have been used for heat-resistant members of aircraft engines, gas turbines for power generation, and the like, especially for turbine discs. The heat-resistant members such as the turbine discs are required to have high-temperature oxidation resistance and also be excellent in strength such as creep strength and fatigue strength.
To meet this requirement, a nickel alloy with high-temperature oxidation resistance provided by the addition of chromium has been proposed. As the nickel alloy, there has been known a nickel alloy containing, with respect to the total quantity, Cr in a range of 2 to 25% by mass, Co in a range of 19.5 to 55% by mass, up to 10% by mass of Mo, up to 10% by mass of W, Ti in a range of 3 to 15% by mass, Al in a range of 0.2 to 7% by mass, up to 0.05% by mass of C, up to 0.05% by mass of B, up to 0.5% by mass of Zr, up to 10% by mass of Ta, up to 2% by mass of Hf, and up to 5% by mass of Nb (refer to Patent Literature 1).
Also, as the above-described nickel alloy, there has been known a nickel alloy containing, with respect to the total quantity, Co in a range of 20 to 40% by mass, Cr in a range of 10 to 15% by mass, Mo in a range of 3 to 6% by mass, Win a range of 0 to 5% by mass, Ti in a range of 3.4 to 5% by mass, Al in a range of 2.5 to 4% by mass, C in a range of 0.01 to 0.05% by mass, B in a range of 0.01 to 0.05% by mass, Zr in a range of 0 to 0.1% by mass, Ta in a range of 1.35 to 2.5% by mass, Hf in a range of 0.5 to 1% by mass, and Nb in a range of 0 to 2% by mass (refer to Patent Literature 2).
Further, as the above-described nickel alloy, there has been known a nickel alloy containing, with respect to the total quantity, Cr in a range of 11 to 15% by mass, Co in a range of 14 to 23% by mass, Mo in a range of 2.7 to 5% by mass, W in a range of 0.5 to 3% by mass, Ti in a range of 3 to 6% by mass, Al in a range of 2 to 5% by mass, C in a range of 0.015 to 0.1% by mass, B in a range of 0.015 to 0.045% by mass, Zr in a range of 0.015 to 0.15% by mass, Ta in a range of 0.5 to 4% by mass, Hf in a range of 0 to 2% by mass, and Nb in a range of 0.25 to 3% by mass (refer to Patent Literature 3).